Tobacco Smoke Enhances the Progression of Diabetic Nephropathy

Using a diabetic mouse model, researchers at the University of Alabama Birmingham report that exposure to tobacco smoke worsens the progression of diabetic nephropathy likely mediated by increased expression of profibrotic cytokines.

Diabetic nephropathy is the most common cause of end-stage renal disease in the U.S. It is characterized by proteinuria, and irreversible changes, such as sclerosis, in the structure and function of the glomeruli, the filtering structures in the kidney. These changes effectively reduce the kidney's ability to filter waste and toxins from the blood by reducing the glomerular filtration surface. Cigarette smoking is now recognized as a risk factor in the progression of chronic kidney disease.

In the current study, the mice were exposed to tobacco smoke for 8 weeks at roughly the same levels as those found in active smokers. Tobacco smoke exposure caused significant increases in mesangial expansion accompanied by increases in expression of transforming growth factor B and fibronectin, as compared to the control group mice that breathed regular air.

These studies demonstrate that smoking and exposure to environmental tobacco smoke may further the progression of diabetic nephropathy. The researchers conclude, based on this and previous research, that nicotine may be mediating these effects. The results suggest that additional targeted smoking cessation efforts may be very beneficial for persons with diabetes.